Pediatric Malignant Solid Tumor

QLC2519 (Mai Li Sheng®) is a new protein drug created by fusing the N-terminal of highly active modified G-CSF with the C-terminal of HSA. The modified G-CSF retained high activity while reducing affinity for the G-CSF receptor, which can significantly inhibit the the G-CSF receptor-mediated (RMC) pathway. The aim of this study is to evaluate the PK/PD characteristics of QLC2519 in preventing chemotherapy-induced neutropenia (CIN) in children with sarcoma.